Dissolving Ag from Au-Ag Alloy Nanoboxes with H2O2: A Method for Both Tailoring the Optical Properties and Measuring the H2O2 Concentration

This article describes a method for generating Au-based nanocages with controlled wall thickness, porosity, and optical properties by dissolving Au front Au-Ag alloy nanoboxes with H2O2 It involves two steps (i) formation of Au-Au alloy nanoboxes with some pure Ag left behind by titrating Ag nanocubes with aqueous HAuCl4 and (ii) removal of Ag at from both the pure Ag remaining in the nanoboxes and the alloy walls via H2O2 etching The optical properties of the resulting Au-Ag nanocages can be easily tailored by controlling the amount of H2O2 added into the reaction system Due to the changes to the optical spectra. the Au-Ag alloy nanoboxes can also be employed to detect H2O2 with a linear readout (R-2 = 0 99) in the range of concentration from 5 x 10(-2) to M down to 5 x 10(-7) M.